Initial revision

1999-04-05 21:32:32 +00:00
parent a0e40c1fc1
commit 1eb87e7c73
136 changed files with 142 additions and 16521 deletions
@@ -0,0 +1,134 @@
+//
+// interpolater.cxx -- routines to handle linear interpolation from a table of
+//                     x,y   The table must be sorted by "x" in ascending order
+//
+// Written by Curtis Olson, started April 1998.
+//
+// Copyright (C) 1998  Curtis L. Olson  - curt@me.umn.edu
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful, but
+// WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+//
+// $Id$
+// (Log is kept at end of this file)
+
+
+#include <Include/compiler.h>
+
+#include STL_STRING
+
+#include <Debug/logstream.hxx>
+#include <Include/fg_zlib.h>
+#include <Misc/fgstream.hxx>
+
+#include "interpolater.hxx"
+
+
+// Constructor -- loads the interpolation table from the specified
+// file
+fgINTERPTABLE::fgINTERPTABLE( const string& file ) {
+    FG_LOG( FG_MATH, FG_INFO, "Initializing Interpolator for " << file );
+
+    fg_gzifstream in( file );
+    if ( !in ) {
+        FG_LOG( FG_GENERAL, FG_ALERT, "Cannot open file: " << file );
+	exit(-1);
+    }
+
+    size = 0;
+    in >> skipcomment;
+    while ( ! in.eof() ){
+	if ( size < MAX_TABLE_SIZE ) {
+	    in >> table[size][0] >> table[size][1];
+	    size++;
+	} else {
+            FG_LOG( FG_MATH, FG_ALERT,
+		    "fgInterpolateInit(): Exceed max table size = "
+		    << MAX_TABLE_SIZE );
+	    exit(-1);
+	}
+    }
+}
+
+
+// Given an x value, linearly interpolate the y value from the table
+double fgINTERPTABLE::interpolate(double x) {
+    int i;
+    double y;
+
+    i = 0;
+
+    while ( (x > table[i][0]) && (i < size) ) {
+	i++;
+    }
+
+    // printf ("i = %d ", i);
+
+    if ( (i == 0) && (x < table[0][0]) ) {
+	FG_LOG( FG_MATH, FG_ALERT, 
+		"fgInterpolateInit(): lookup error, x to small = " << x );
+	return(0.0);
+    }
+
+    if ( x > table[i][0] ) {
+	FG_LOG( FG_MATH, FG_ALERT, 
+		"fgInterpolateInit(): lookup error, x to big = " << x );
+	return(0.0);
+    }
+
+    // y = y1 + (y0 - y1)(x - x1) / (x0 - x1)
+    y = table[i][1] + 
+	( (table[i-1][1] - table[i][1]) * 
+	  (x - table[i][0]) ) /
+	(table[i-1][0] - table[i][0]);
+
+    return(y);
+}
+
+
+// Destructor
+fgINTERPTABLE::~fgINTERPTABLE( void ) {
+}
+
+
+// $Log$
+// Revision 1.1  1999/04/05 21:32:33  curt
+// Initial revision
+//
+// Revision 1.7  1999/02/26 22:08:03  curt
+// Added initial support for native SGI compilers.
+//
+// Revision 1.6  1999/01/27 04:46:16  curt
+// Portability tweaks by Bernie Bright.
+//
+// Revision 1.5  1998/11/06 21:17:27  curt
+// Converted to new logstream debugging facility.  This allows release
+// builds with no messages at all (and no performance impact) by using
+// the -DFG_NDEBUG flag.
+//
+// Revision 1.4  1998/05/13 18:24:25  curt
+// Wrapped zlib calls so zlib can be optionally disabled.
+//
+// Revision 1.3  1998/04/25 15:05:01  curt
+// Changed "r" to "rb" in gzopen() options.  This fixes bad behavior in win32.
+//
+// Revision 1.2  1998/04/22 13:18:10  curt
+// C++ - ified comments.  Make file open errors fatal.
+//
+// Revision 1.1  1998/04/21 19:14:23  curt
+// Modified Files:
+//     Makefile.am Makefile.in
+// Added Files:
+//     interpolater.cxx interpolater.hxx
+//